


Secession

by Cryptid495



Category: Arrow (TV 2012), Supergirl (TV 2015)
Genre: F/F, Spoilers for Crisis on Infinite Earths Crossover Event (CW DC TV Universe), it's the end of the world as we know it, kara drops everything (including people) when lena calls, lena has some pretty intense doctor who energy
Language: English
Status: Completed
Published: 2021-02-17
Updated: 2021-02-17
Packaged: 2021-03-13 03:47:06
Rating: Teen And Up Audiences
Warnings: Major Character Death
Chapters: 1
Words: 3,976
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29520378
Author URL: https://archiveofourown.org/users/Cryptid495/pseuds/Cryptid495
Summary: Lena tells Kara to drop everything, and despite the hurt between them, she does.---Huge thanks to AO3 user JoClbs for helping me with my French, being English I am very very bad at it and very much needed the help. Go check out her works!
Relationships: Kara Danvers/Lena Luthor
Comments: 13
Kudos: 53





	Secession

“Kara. Here. Now.”

The frequency ripped behind Kara’s eyes, drove railroad spikes into her temples. She dropped The Deserter without even thinking and catapulted herself above the skyscrapers and into registered airspace, where the winter evening air was cold enough to soothe the pain just a little.

The Kryptonian Beacon. Lena’s voice, shaking hard.

“I’m sorry, I know this is hurting. I need you here, right now. Please. L-Corp R&D. I’ll call again in one minute.”

Simple enough. Kara shook the last of the beacon fog out of her mind and cracked through the sky. She was at the L-Corp tower in less than a second, at ground level and in the underground car park in two. One more to tear the door off the service elevator, and another to jet down to the deepest sub-basement level and take the doors off that too.

Lena, surrounded by machinery. Half of it screaming, beeps and whistles and tones all calibrated for human attention - thankfully none of it even close to the Beacon’s effect on her.

Lena didn’t even blink as the elevator doors screeched across the floor.

“Hi?” Kara said. “It sounded urgent?”

“Physics!” Lena yelled. She pulled a lever and a fat spark cracked out of a connected block of machinery - and a new graph appeared on a blank screen, something that looked like a cross between a spectrograph and a flatlining EEG. “It’s… well, look! It’s fucked!”

She had to suppress a snort. Lena  _ never _ swore.

“Redshift stopped about an hour ago,” Lena chattered. “I mean  _ stopped _ . The universe  _ stopped expanding _ , Kara. Physics just… broke. Look, this one? CMBR. Literally flatlined about... “ and she looked closer at the screen she’d just fired up. “...ten minutes ago? Ish? Come on, you’ve surprised me with your knowledge before, give me something - anything - to reassure me this isn’t… I don’t know, cataclysmic quantum foam failure? Because it certainly  _ feels _ like the end of the world.”

“That’s three counts of whiplash in the last thirty seconds. Rao, I’d forgotten how much fun it was to be on the same side.”

“You’re Kryptonian, what could possibly give you whiplash?”

“At last count? Direct meteor strikes, and you.”

Lena grinned wide. “God I’ve missed you. But now, think!”

“CMBR flatline? Expansion at zero? So what, probably Hypothetical Macrophysics and Stellar Engineering?” Kara closed her eyes, tried to remember.

“I don’t mean to rush you but every radioactive isotope is decaying all wrong and my guess is it’s about fifteen minutes before they all lose cohesion.” Lena glared at a rack of mineral samples, flicked the one labelled C-14 with a disapproving cluck.

“Okay, okay! So, Stellar Engineering was kind of like… architecture, I guess? Earth architecture assumes gravity at 9.8 Newtons per second per second, and Stellar Engineering likewise assumed that you would always know the applicable redshift for whatever hypergate you were setting up. CMBR was kind of… just always there? Hyperliminal data attenuates through CMBR-saturated space so you needed to know when the waves would hit for surge protection, but there’s nothing anywhere in my memory about what either of them actually  _ mean _ . And, uh. I hated the Hypothetical Macrophysics teacher. I swear I’m trying to remember. Colletan’s Conjecture… no, that was about quantum tunneling. Uh, Nurei’s Third… maybe? That one was universal resonance, it postulated that the resonant frequency of the universe could be used to measure it…?”

“Promising! Run me through it?”

“...It kind of depends on having a hydrogen fusion reactor to hand?”

“Damn. Okay, can we look at anything el-”

Kara looked over and found Lena standing right in front of her, peering up at her face with just a little mania darting behind her eyes.

“You,” Lena said. “Your powers. I’ve had a pet theory for a long time. There were notes on Rao in the data Cadmus stole, way back when. I booked some time on the VLA and ran a full spectro on it out of curiosity and I got some odd readings and now I think maybe I might be right. Would you try using your eyes please? On a non-load-bearing wall, that would be ideal.”

“...I guess so, but why?”

“What was it you called it? Stellar Engineering. I think Kryptonians have a spatial link to Rao embedded in them. Your weakness to Kryptonite matches two things we know for certain; that Rao emits none of the wavelengths associated with krypton - the noble gas, not the planet - synthesis, and that Kryptonite itself… shouldn’t work, but somehow does. It’s a noble gas, it can’t form minerals. You can  _ sort of _ make a very explodey acid with it - krypton octafluoride - but, y’know, don’t. I think that Rao was always charging you, and it was Krypton itself - the planet this time, not the gas - that was depleting you again. It would certainly explain how you were a Kardashev 2 civilisation without even a Dyson plate to your name.”

“So, just… blast off a bit of concrete?”

Lena nodded vigorously. “I can scan it afterward. If I’m right, I have a couple of ideas.”

She did as Lena asked. A chunk of wall came down, charred and still glowing just a little from the heat. Lena grabbed a featureless device from a huge box of similar but not quite identical featureless devices, hunkered down and scanned.

“Yes. Yes! That’s it! First up - you’re still connected to Rao. That means it still exists, and the connection still works. But secondly this means krypton batteries! The gas, not the planet!”

“I’m… I think I… no, I’m lost.”

“Your eyes output so much energy. A tank of krypton octafluoride, an absolute ton of power storage, and a weak-force disruption emitter. That ought to do it.”

“Wait… you’re going to cut us off from the rest of the universe?”

“Kara, the laws of physics are  _ failing _ . You know how I said radioisotopes are all degrading? Nuclear plants are already failsafing worldwide, within five minutes there’ll be global brownouts. We won’t be able to rely on the terrestrial power network and anyway, if this works, we won’t be able to get electricity from outside the shell. C-14 is affected, and that means the nuclear forces within carbon itself are affected, and that means the end of all life. There are only eight weak-force disruption emitters in the world and it is a matter of sheer luck that L-Corp happens to have one right now. I rig that up to a whacking great capacitor and take a tank of krypton octafluoride with platinum and lead vanes, you can dump gigajoules into the tank with a half-second blast and it might be enough to save… well, this room.”

“What about everyone else?”

“I don’t… Kara, I don’t know. I don’t even know if this is going to work but as Hail Marys go, it’s my best shot. If it works, we can try to expand the shell? But even Supers are governed by four thirds Pi r cubed and the inverse square law, you’d solar-flare before you output enough power to push the shell much further than a hundred metres out.”

“Okay… okay. What do you need?”

“Fluorine. Gallons of it. We might have enough in storage down thataway,” and she gestured towards grey double-doors marked STOCK, “but if we don’t, you’ll have to go break in to Lord Tech, they have tons of the stuff.”

Kara started fetching things, putting them where-ever Lena needed them. Tanks of fluorine, sheets of lead and platinum plating, entire banks of battery packs. Every time she came back Lena had wired more things into other things, and also seemed to have built two distilleries, one small one for Kryptonite and sulfuric acid, and one that bubbled the output through liquid fluorine on its way to a lead-lined tank.

“Wait, Kryptonite?”

“I know, I know. We still had huge stockpiles of the stuff and in my defence I did hate you. It’s all behind lead glass, it shouldn’t be affecting you. Now if I were to ask you to connect all those portable battery walls to one another in parallel, how quickly could you do it?”

The first rumble.

A light in the corner of the room turned off.

Lena gaped.

“That was KSU, in Saudi Arabia. It’s… gone.”

More lights followed.

“Kara. Kara, we have minutes, do you understand me? Minutes. Parallel connection on those battery walls, go.”

She did.

“Battery walls, transformers, weak force disruptor.” Lena pointed to a few things in order as she conducted the elaborate and painstakingly slow glass orchestra that was her distillation equipment. “Everything’s labelled, daisychain the transformers until they go from one to the other.”

She did.

“Alright. Get me the inbound cable to the battery walls, extend it over here, then rip the end off and strip the last twelve inches of the red and black wires - we need direct metal connections to the anode and cathode, understood?”

She did.

“Alright.” Over half the lights on the distant board were gone. “Nearly ready. The moment the tank is full, cover it with this and weld it shut.” She held up another piece of leaded glass, bezeled with steel.

Kara nodded, lips dry. She stared at the board as more lights went out, winced as the seismic rumbling grew and the distillation equipment clattered.

“Now!”

She placed - not slammed, because she knew how she broke things when she went too hard - but  _ placed _ the lead glass lid on the tank, and ran her eyes around the edge.

“Good.” Lena tapped it a couple of times, sloshed it to see if anything came out. “Perfect. Now I need you to sink a half-second of full-power eye lasers into the middle of the tank.”

“Are… are you sure I won’t break it?”

“Kara, we have about two minutes until whatever this is reaches us. This is the last shot, right now. If it breaks then I messed up and I won’t be able to fix it in time anyways. So go for it.”

She did.

The beams of light from her eyes became thick glowing slugs of green, which rapidly expanded to fill the tank. A low whining sound came from the battery walls as green lights flickered on, showing them all charged or charging.

Lena stood in front of the weak force disruptor now, working switches and buttons and muttering to herself. Lights on the distant panel kept going out, the ground shuddered beneath their feet, parts of the device started spinning and screeching. Lena cranked two more dials, lifted a switch cover and slammed her hand down on the giant red button underneath it.

The earthquake stopped. Lena whooped, grabbed Kara by the face and kissed her.

The lights on the distant panel kept flickering out, until only one remained.

An unnatural white glow crept beneath the stock room doors, and flowed down through the elevator shaft that Kara had come in through.

And everything was quiet.

Lena let go of Kara’s face, broke the kiss, looked extremely sheepish.

Kara’s cheeks burned.

“Sorry,” Lena whispered. “I’ve never created a pocket dimension before. I feel damn powerful right now.”

“You  _ are _ .” Kara couldn’t keep the admiration out of her voice, nor, she realised, would she ever want to. “You always have been.”

“You’re damn right,” Lena chuckled, something broken under the sound.

Kara held her.

“I’m so sorry,” she murmured.

Lena glared up at her.

“Hear me out,” Kara said. “I think I understand now. You were always home to me. I always loved you. And Alex kept telling me and I kept brushing it off because you’re so capable, and strong, and clever, and you know so many better people than me… but Alex kept telling me that you felt the same way, and I didn’t believe it. But if I put that to one side, if I let myself believe that I was love and home to you as well… then how can I not understand, how much it hurt you to find out I’d been lying all along?”

Lena burrowed in under Kara’s chin and completely failed to crush her in a very tight hug. “You were everything.” Her voice was muffled. “And I don’t know. I wish you’d told me, before Lex managed to. Or maybe I wish I’d shot him in the head, rather than the chest. I wish a lot of things.”

“We all do.”

Lena jolted back out of the embrace, and they both turned to the new voice. A figure wrapped in fabric that pulled strangely at the light around it, that was somewhere between dark green and the inside of a black hole.

“What the hell…?”

“I thought nothing could get in here?”

Lena was the one who stepped forward first, peering at the figure as it resolved into -

“Oliver Queen?”

The man in the hood nodded. 

There was a gravity to even that motion that had Kara ready to step back, to listen - but Lena in all her fire had no such compunction, and stepped right into his space. “Physics is broken, the Earth is gone, and of all the people out there who could have shown up, it’s you?”

“Lena, you can’t just-” Kara stammered.

“Of course I can! The Green Arrow has no powers! He’s notorious for exactly that reason!” Lena poked him in the chest. “So howcome, with all the breachers and the interdimensional tech out there, the only person who finds us is him? Would you care to answer that, Mr. Queen?”

“I…” And his voice was deep, sepulchral, undertoned with something else. “It’s a long story. Earth-27 - your Earth - is gone. All Earths are gone. There are pocket dimensions outside of the Multiverse but I cannot open the path to them - they will be consumed by antimatter if I do. And so I am left with you, a single twenty-metre sphere of old universe that must yield to allow the new multiverse to come into being.”

“And what makes you think we will yield? For as long as Rao exists - and we know that whatever is ending the universe is moving at what, ballpark 0.01c, so it won’t reach Rao for a very, very long time - Kara can keep recharging our emitters, we can maintain the shell.”

“And is there enough food in here to keep you alive, Lena Luthor?”

“Fuck!” Lena bellowed at the ceiling.

“I’m not going to starve you out,” Oliver said. “I would like to save you, if I can. But I need you to understand. The new Prime universe that I am weaving… it already has a Kara Danvers, and a Lena Luthor.”

“Then change our damned names. I will not die here, Queen.”

A moment of quiet.

“I... can... rewrite you. But you will have to trust that the Kara and the Lena already in that world are the ones who should be there. Be at peace with the fact that your lives in those shoes are over. You will no longer have access to the Luthor holdings. And you will no longer be Kryptonian. You cannot remember your lives as they are now, or the people you are connected to. There is nothing of this Earth left beyond this room; I am so sorry. They are all gone, and their Prime counterparts cannot know of you.”

“...what  _ can _ we keep?” Tears ran down Lena’s cheeks. “I can’t believe this was futile. A Luthor and a Super stopped the degradation of this universe in its tracks. We survived past the end of all things. If you’re telling me it was for nothing, that we can keep… nothing? Then I won’t ever forgive you, Queen.”

Kara took Lena’s hand, and squeezed, and spoke. “Each other. If everything else is gone and we’re not allowed to remember it in this new prime reality… can we at least remember everything we’ve had with each other?”

Lena choked. “Darling,” she rasped out. “You are making me ugly-cry in front of someone who might yet turn out to be an enemy.”

“You’ll forgive me.” Kara smiled.

“Thin ice, Super. But yes.”

“...where do you want to live?” Oliver’s voice was finally something more than calm. He was curious, now, and maybe even optimistic.

“We can’t stay near National City. How do you feel about Canada?” Kara squeezed Lena’s hand again. She had always heard it was nice up there.

“I can’t go back to the UK, and you’re right, the mainland US is probably a bad idea. And as much as I hate it, we won’t remember anyone else to miss them...”

Oliver nodded, back to solemn now.   
  
“Toronto,” Kara said. “And Lena gets to be a professor in the university’s engineering department.” She felt Lena’s eyes on her. “I read somewhere that Toronto’s university is really good for engineering. And I can’t think of any other place where Lena could keep using her mind as much as she does for L-Corp. And you can’t take away her intellect.”

“And you can’t take Kara’s hope.”

Something amused Oliver; he smiled, just a little. “Wouldn’t dream of it.”

The Rao Capacitor bleeped.

“Thirty seconds. Kara, would you recharge it please?”

“There’s no need. You’ll keep these memories as dreams. Just a couple more questions. Dog or cat?”

“Dog!”

“Cat.”

They pulled faces at each other.

“One more. Daughter or son?”

Lena’s jaw slackened in shock, and Kara felt her own doing the same. But Lena’s hand was right there, resting in hers so perfectly, that Kara couldn’t help but regroup. A thousand thoughts ran through her mind as she squeezed gentle, raised Lena’s hand to her lips and kissed soft.

“Daughter?” She asked.

“It’s a very reductive question. But… yes. Daughter,” Lena croaked, tears falling free now.

And Oliver nodded, and the Rao Capacitor failed with a crack, and everything around them dissolved to white and burning and particulate fire.

  
  
  
  
  


Keira Lemarchal-Dean snapped upright. Drenched in sweat, heart pounding, mind full of loss and grief and fear - one hell of a nightmare. She felt the details falling away, and waited until her breath came soft again, and leaned over and kissed her wife’s hair. Lucille slept light enough that heavy breath was enough to wake her some days.

She rolled over and picked her way carefully out of their bed, and even more carefully out of their room.

The cat thumped head-first into her ankle, his rough little purr turned into a chirp by the impact. “Good morning, Alex.” Keira kneeled down for a moment to ruffle Alexander Meowington between the ears, then kept on to the kitchen. Scant morning light filtered in through the windows, scattering lines of gold over the kitchen surfaces and the carpet... and the dog, who was on the couch again.

“Off, my love. Off now.” Keira grabbed a lint roller from under the coffee table, gently shoved at Valjean. He let out a low boof and trundled off to his corner bed and curled back up, looking up at her reproachfully.

She looked up at the little clock, a gift from her parents. Quarter to six. No point trying to go back to bed, but too early to get away with a morning smoothie. She settled for second best - a chopped banana, a sprinkling of nuts and raisins, a third of a pot of greek yogurt.

She hit the couch, grabbed the remote, muted the TV before it could make any noise.

Live-broadcast subtitles staggered their way across the screen as some combination of AI and human eyes confirmed what the US President was saying on the news. Lucille would know what algorithm they were using. She would vent - and had vented a few times before - about the various worldwide attempts at voice recognition AI, how Lexcorp probably had the edge but only because they still committed vast data breaches in the name of gaining more training data, how AI was still exactly as bigoted as the people who assembled the test data, how Palmer Tech was probably the best at fighting against that tendency, how -

_...inform you that Oliver Queen sacrificed his life… _

The nightmare surged in her throat, rushed up behind her eyes. She and her wife standing in a smashed-up laboratory, facing a man in green who had come to bargain with them, to finalise the end of the world. And then everything that came before that, rolling backwards. Lucille holding her down, torturing her, poisoning her. Broken by her own hand and screaming grief and fury at her. And before that… working together, fighting together, being together and at the beginning of it all, a sea of flowers.

“Qu’est-ce qu’il y a, mams?”

Keira yelped, rubbed the tears away from her cheeks and eyes. “Ria, honey, I didn’t know you were up?”

“I wasn’t.” She pointed down to Keira’s feet, where a shattered bowl of banana and yogurt and other very messy things lay on the carpet. “You want some of your breakfast gunk to replace that?”

“Please. Can you throw me some cleaning supplies while you’re over there?”

“Sure, sure. Coucou, maman!"

Lucille blinked a few times as she trudged into the room, then smiled wide. “Coucou, Ria. Quel était ce bruit?”

“Mams a mis le bordel,” Ria said in the perpetually slightly bored tone of a tired eleven-year-old, before hurling a few items across the room.

“...Hey!” Keira snagged the kitchen roll, scrubbing cloth, carpet cleaner, and a small plastic bowl out of the air.

“She’s not wrong.” Lucille yawned, leaned down, kissed Keira softly. “Bad dreams?” she murmured when she was close enough for Ria not to hear.

“...really, really bad dreams.” Kiera grabbed her hand and squeezed it.

“Tell me later?”

“Mmm.”

Kiera got to cleaning as her wife and their daughter worked in the kitchen. The smells of coffee and eggs and her usual morning strawberry and protein smoothie built up as she cleaned, and by the time she was confident that she’d finally blasted the last of the gunk out of the carpet, Lucille and Ria were on the sofa beside her and their drinks and breakfasts were all lined up on the coffee table.

She took the bowlful of detritus to the kitchen and tipped the contents into the garbage, washed the bowl, left it to dry and came back to her family.

She saw a tear on Lucille’s cheek. Leaned in and kissed it carefully away. Nestled her head onto her wife’s shoulder and watched the last of the morning news.

And the morning carried on as mornings always did. Ria got ready for school, Lucille got ready for work, and Keira tidied up around them. It was far easier to hold off her morning routine until they’d both left, blog article writing wasn’t a precise 9-to-5 job after all. The morning went mostly okay, aside from the cat mauling Lena’s shoelaces when she was getting ready to leave, earning him an affectionate “Sod off Lex, you little shit.” and a scratch behind the ears.

And they kissed at the door, and suddenly Keira was alone.

She set up her laptop, threw herself down on the sofa, turned the TV back on, and patted the cushion next to her. “Hey, Jean-jean. I could really do with some company. I’ll have to push you off and clean it again before maman gets home, but for now... come on, boy.”

The big old golden retriever hopped up on the couch and curled up next to her, moving only to rest his head on her lap a few minutes later as she started to cry, as deep nameless ancient grief poured out of her.

It wouldn’t last. She knew that somehow. But she also knew that it felt too important to suppress, that she should respect its enormity and let it out.

So she wept.

**Author's Note:**

> I’ll close this one up with a quote that is often misattributed, but not so much as to be completely inaccurate.
> 
> “Do not be daunted by the enormity of the world’s grief.  
> Walk humbly now.  
> Do justly now.  
> Love mercy now.  
> You are not expected to complete the work,  
> but neither are you free to abandon it.”
> 
> It is often ascribed to the Pirkei Avot, and it does have its origins there. Rabbi Tarfon wrote an interpretive translation of the Pirkei Avot which was later paraphrased by Rabbi Rami Shapiro, and it is that later paraphrase that appears above.


End file.
